I replaced Sony 170 with the Panasonic HMC80 mainly to take advantage of the SD card workflow.
On my small set with Rifa lights the Sony was at f/4. The HCM80 requires digital gain up to 9 db to get adequate levels. I added fluorescent lights to boost the level of lighting. There's a LOT of light in the small area and I still need 3db gain.
Am I missing something?
The DCR-PD170 has three 1/3" sensors.. they are going to collect more light in the same situation than the 1/4" sensors of the HMC80. And in fact, it might just be significant. Light gathering is based on pixel size. For a DV camera, the pixels could be about 6x the size -- meaning, 6x the light gathering capability, all things being equal -- versus an HD camera with the same sensor size.
That's not to suggest things are always equal. The CMOS sensors in the HMC80, while smaller than those of the PD170, are lower noise at the same gain level. So you get a little of that back. If you downrez to DV, you'll effectively average out much of the noise, so when comparing apples and apples, the PD170 will still be better in low light, but it shouldn't be critical.
Incidently, the HMC80 doesn't have "digital gain", the gain you're adding is analog, same as the gain on any camcorder. You're tweaking the gain on the ADCs that take the analog signal from the pixels and convert it to the digital signal that's ultimately recorded. It took several iterations to get CMOS sensors working well, but by the time the HMC80 came out (it has the same sensor array as my HMC40.. it's actually the first good "cheap" shoulder mount camera Panasonic made; all the previous ones were generally lower in quality than a good consumer camera of the same era), CMOS sensors were quite a bit quieter than CCD. So adding a bit of gain is not in itself a problem.
The bottom line: how does you video look?
Now, also consider that among DV camcorders, the PD170, VX2100, and other cameras based on the same tech were probably the best low-light models ever made. Sony didn't win on features, pretty much ever, but they were ahead of Canon, Panny, and JVC on low light back in that era. The HMC80 is definitely not in the same league. When I need low light video, I use my Canon 60D HDSLR, and just deal with the 10-12 minute recording window. HDSLRs are better at low light than pretty much any camcorder, though of course with many more issues, workflow-wise.
Thank you, Dave. I had no idea that I was going to receive such a thoughtful and detailed response.
When I get the exposure set correctly, the picture looks fine, even with the added gain. My impression is that the Sony 170 was more forgiving with exposure settings, too.
The in-studio segments of the show I produce are in SD, and the HMC80 will record standard DV onto the SD card, so I don't down convert from HD.
Everything that I do outside the studio is HD now so I can save it to re-use it later, but for now the show goes to the TV station in SD, so I do down convert the on the road footage.